Is someting wrong with my PowerBook?

Hello,

I just woke my PowerBook(stats in signature) from sleep, and when i opened iTunes, a horrible hissing noise erupted from the speakers. Is this Normal? Should i get it looked at (it also has a squeaking space bar)?

Thanks for your help

So far, only once (the computer only just came into full time service about a month ago, and when i woke it from sleep, it happened. I don't know what the problem is, is it serious?